Thursday, March 03, 2011

One To Grow On

We're always looking out at the universe for signs of life, but I've got an idea to help anyone who might be out there find us. And I don't mean putting a capsule on the moon with people saying Hi in every language or whatever.

Okay, so we get some giant thing and we wave it in front of the sun in a non-random way. Like Morse code-style. So anyone looking from far away will see this one star (our sun) blinking on and off in an obvious pattern that had to be done by a living creature.

I know what you're thinking: that I'm mildly retarded. But let me answer some of your questions:

1. Yes, I know it takes a long time for light to travel. So we do our little code and then in a few hundred years, see if we get any feedback. At that point it'll be like those old-school chess games people used to play with each other through the mail, but it's better than nothing. Hopefully the creatures that notice our blinking star are relatively close, so we'll get their answer back in hundreds as opposed to thousands of years. (Or maybe they've got spaceships ready to fly, and now they'll know which star to fly toward.)

2. Yes, I know the sun is really big and I can't build a big thing in my back yard that would block it out. But we could build something relatively big that we could put far enough out in space so that it, at the very least, can block out some of the sun's light, from the perspective of someone looking at it from far away. Right? (But if a planet going in front of the sun looks tiny, I guess my mystery object would have to be at least as big a planet....)

Or maybe we could build a giant structure in the shape of a face profile, and put it on the moon so that it would show up if someone was looking at the sun from far away, like a little black dot with a tiny face on its edge going across the light.

Blocking a portion of the sun's light so that it would be detectable from far away certainly isn't impossible, and looking for this is what is known as the Transit Method of extrasolar planet detection. NASA's Kepler mission, for example, is currently finding planets around other stars by looking for regular dips in the brightness of stars caused by planets passing between us and the star. Right now the smallest thing they've detected that way is still many times the size of Earth, but techniques will get better and better over time (and the longer the mission lasts the more orbits it will be able to see).

The problem is actually the dynamics and the geometry of the idea. Even assuming we could build an Earth-size disk it would still have to orbit the sun to avoid falling into it. And what direction would we direct the signal towards? But if you somehow had enough energy to move this thing around erratically though, for long enough, it could be observed as not obeying natural motion.

I once heard a professor propose redirecting the massive amount of light from a supernovae to other stars, as a way of showing that intelligent beings built something that can...redirect the light from supernovae...

Mom here.Jeeze, Jere, don't you want to sit down and immediately write a science fiction novel/script based on Ryan's cool and provocative explanations of things which would convince the the most cynical cynic that we can do anything as long as Ryan is directing?

Haha, thanks Jere's Mom! It just so happens that I've gotten a bit of experience explaining *this exact thing* as my advisor and I recently helped with putting together a museum exhibit about finding extra-solar planets. Which is very similar to what what it would take to find the signal you're describing!